MECA believes, however, that EPA should also harmonize with California’s implementation date of 2008 for the Tier 2 standards, rather than delaying implementation by two years.
EPA’s proposed standards for Class I and Class II motorcycles could be strengthened by adopting standards that are based on the control capabilities of proven catalyst technology. One possible approach would be commit to harmonize the U.S. standards for Class I and Class II motorcycles with the European Commission’s 2006 standards.
MECA believes EPA’s suggestion of extending the useful life requirements up to 40,000 km for Class III motorcycles is technologically feasible. Catalyst technology can be applied to help Class III motorcycles meet emission standards for extended periods.
MECA recommends that EPA establish Blue Sky Standards in the range of 0.4 g/km HC+NOx for Class III and 0.5 g/km HC for Class I and II motorcycles to promote the technology development of and provide opportunities for additional emission control from highway motorcycles.
Catalyst technology is well developed for highway motorcycle application in the U.S. As discussed below, catalyst technology combined with improvements in engine and fuel delivery system design has been applied to two- and three-wheel vehicles powered with spark-ignited two- and four-stroke engines for a number of years throughout the world and has provided significant emission reductions of HC+NOx, CO, and, in the case of two-stroke engines, PM emissions. Objections to applying catalyst technology to two- and four-stroke motorcycles have included durability, packaging constraints, safety, performance, and cost of the systems. Actual commercial experience with both two-stroke and four-stroke two-wheel vehicles has demonstrated that all of these concerns are easily addressed.
September 17, 2002